Why was Ginkgo once grouped with conifers in older classification systems?

In older systems of biological classification, Ginkgo was placed in the class Coniferopsida alongside conifers (such as pines, firs, and spruces) because both groups share certain general characteristics, such as being woody, seed-producing trees.1

However, modern botanical classification recognizes Ginkgo as a distinct group, now placed in the division Ginkgophyta. This change reflects the understanding that while the ancestral stock of Ginkgo dates back to a time coordinate with the ancestors of the conifers, the two groups appear to have evolved independently.1

Key differences that distinguish Ginkgo from conifers include:
* Reproductive Biology: Ginkgo is dioecious (having separate male and female trees), whereas many conifers are monoecious. Furthermore, Ginkgo produces motile, multiflagellated sperm, a primitive trait it shares with cycads but not with conifers, which produce non-motile sperm.12
* Morphology: Ginkgo possesses unique fan-shaped, dichotomously veined leaves and distinct spur branches, which differ significantly from the needlelike or scale-like foliage typical of most conifers.13